PREFACE 



interest when we are told that a sparrow hawk 

 captures ten score field-mice a year and innum- 

 erable grasshoppers. Yet those very sparrow 

 hawks save the American farmer considerably 

 more than the combined worth of the fishery, the 

 oyster-bed, and the manganese-mine together. 



A large amount of valuable matter has been 

 written on the economic relations of birds to ag- 

 riculture, their relation to man as game birds, 

 domesticated fowl, producers of guano, ornamen- 

 tal plumage bearers, cage birds, and food. But 

 each of these is a specialized field and has been 

 treated separately as such. One to obtain infor- 

 mation concerning the agricultural value of birds 

 is compelled to turn to a treatise on economic or- 

 nithology; for their domestication you must pur- 

 sue a poultry book ; other volumes deal with game- 

 birds and game-laws, with cage birds or ornamen- 

 tal plumes. 



In the following pages the author has endeav- 

 ored to discuss the importance of bird life to man- 

 kind in all its economic phases. Owing to lack of 

 space, he has not laid particular stress either up- 

 on its effect on agriculture or upon the domestica- 

 tion of the fowl. These are admittedly the most 

 important functions of bird life from man's point 

 of view and have been largely dealt with in other 

 Volumes. The author contents himself with rather 

 a brief resume of these functions and passes on 

 to less notable, though highly important, fields. 



